Little advice needed.

'74 Valiant 318 with a 904. I hade to replace the intake manifold gasket, took everythign apart, replaced, then put it all together. Waited for everything to set then gave it a quick drive around the block. Shifted a little harder at 22 mph than in the past, but didn't go over 40.

Took it out the next day and it would shift again when I started to go faster. Plenty of clean fluid in the trans. Did I not hook up the linkage correctly? I have to crawl under it tomorrow to start looking for a fix.

Any help appreciated.

Tim